Inliners International
Posted By: tom jennings wasted-spark with breaker points ! - 03/01/12 12:12 AM
Having just installed a Ford EDIS wasted spark system on my nashcan six, it occurred to me how incredibly easy it would be to fab up an extreme performance breaker points based ignition.


Picture three flat disc cams, a cam bump (increased radius) for about 90 degrees. Stack them up, spread the cams out 120 degrees. Mount this stack to the crank pulley.

Line up three breaker points up side by side, so each is bumped by one of the cam discs.

Add a spring and flyweight system to rotate the disc stack relative to the crank for mechanical advance. Slide the contact points with a vacuum diaphragm for vacc advance if needed.

Wire the three points to an EDIS coil pack. There's nothing high-tech about them, just transformers. Each coil drives cylinder pairs that are physically in the same position but two Otto cycles away (eg. compression + exhaust).


Now for a six banger you have three *simple* ignitions, each running at 1/3rd crank speed. Plus, you have up to 120 degrees of dwell to charge the coil. FAT HOT CHEAP SPARK.

Done and done.

*** Why wasn't this done in 1950? 1960?
Posted By: panic Re: wasted-spark with breaker points ! - 03/01/12 01:21 AM
They accounting department decided that the extra $1.35 cost per car would annoy the stockholders.
Posted By: Tony P Re: wasted-spark with breaker points ! - 03/02/12 03:39 PM
Modern electronics the size of a gnat have eliminated all that monkey motion.
Now you have three sets of points to keep gapped properly.Just before reliable electronic igniton was used in racing,tuner Smokey Yunick tried 8 sets of points to increase ignition dwell on Nascar V8's.
Want a better old school ignition,go magneto with it's long spark duration.
 Originally Posted By: tom jennings
...Mount this stack to the crank pulley.

*** Why wasn't this done in 1950? 1960?


I think you'd be adding a couple three inches to an already long engine.
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